<template>
  <div id="home">
    <nav-bar class="home-nav"><div slot="center">购物街</div></nav-bar>
    <tab-control
      :titles="['流行', '新款', '精选']"
      @tabClick="tabClick"
      ref="tabControl1"
      class="tab-control"
      v-show="isTabFixed"
    />
    <scroll
      class="content"
      ref="scroll"
      :probe-type="3"
      @scroll="contentScroll"
      :pull-up-load="true"
      @pullingUp="loadMore"
    >
      <home-swiper :banners="banners" @swiperImageLoad="swiperImageLoad" />
      <recommend-view :recommends="recommends" />
      <featureView />
      <tab-control
        :titles="['流行', '新款', '精选']"
        @tabClick="tabClick"
        ref="tabControl2"
      />
      <goods-list :goods="showGoods" />
    </scroll>

    <back-top @click.native="backClick" v-show="isShowBackTop" />
  </div>
</template>

<script>
import HomeSwiper from "./childComps/HomeSwiper";
import RecommendView from "./childComps/RecommendView";
import FeatureView from "./childComps/FeatureView";

import NavBar from "@/components/common/navbar/NavBar";
import TabControl from "@/components/content/tabControl/TabControl";
import GoodsList from "@/components/content/goods/GoodsList";
import Scroll from "@/components/common/scroll/Scroll";
import BackTop from "@/components/content/backTop/BackTop";

import { getHomeMultidata, getHomeGoods } from "@/network/home";
import { debounce } from "@/common/utils.js";
import { itemListenerMiXin } from "@/common/mixin.js";

export default {
  name: "home",
  components: {
    HomeSwiper,
    RecommendView,
    FeatureView,

    NavBar,
    TabControl,
    GoodsList,
    Scroll,
    BackTop,
  },
  data() {
    return {
      banners: [],
      recommends: [],
      goods: {
        pop: { page: 0, list: [] },
        new: { page: 0, list: [] },
        sell: { page: 0, list: [] },
      },
      currentType: "pop",
      isShowBackTop: false,
      tabOffsetTop: 0,
      isTabFixed: false,
      saveY: 0,
      itemImgListener: null,
    };
  },
  computed: {
    showGoods() {
      return this.goods[this.currentType].list;
    },
  },
  created() {
    //1.请求多个数据
    this.getHomeMultidata();

    //2.请求商品数据
    this.getHomeGoods("pop");
    this.getHomeGoods("new");
    this.getHomeGoods("sell");
  },
  mounted() {},
  mixins: [itemListenerMiXin],
  methods: {
    /* 
    事件监听相关方法
     */
    tabClick(index) {
      this.currentType = Object.keys(this.goods)[index];
      this.$refs.tabControl1.currentIndex = index;
      this.$refs.tabControl2.currentIndex = index;
    },
    backClick() {
      this.$refs.scroll.scrollTo(0, 0, 500);
    },
    contentScroll(position) {
      //1.判断BackTop是否显示
      this.isShowBackTop = -position.y > 1000;
      //2.判断tabControl是否吸顶
      this.isTabFixed = -position.y > this.tabOffsetTop;
    },
    loadMore() {
      this.getHomeGoods(this.currentType);
    },
    swiperImageLoad() {
      this.tabOffsetTop = this.$refs.tabControl2.$el.offsetTop;
    },

    /* 
    网络请求相关方法
     */
    getHomeMultidata() {
      getHomeMultidata().then((res) => {
        this.banners = res.data.banner.list;
        this.recommends = res.data.recommend.list;
      });
    },
    getHomeGoods(type) {
      const page = this.goods[type].page + 1;
      getHomeGoods(type, page).then((res) => {
        this.goods[type].list.push(...res.data.list);
        this.goods[type].page += 1;

        //下拉加载度多次
        this.$refs.scroll.finishPullUp();
      });
    },
  },
  activated() {
    this.$refs.scroll.scrollTo(0, this.saveY, 0);
    this.$refs.scroll.refresh();
  },
  deactivated() {
    this.saveY = this.$refs.scroll.getScrollY();

    //取消全局事件监听
    this.$bus.$off("itemImageLoad", this.itemImgListener);
  },
};
</script>

<style scoped>
#home {
  height: 100vh;
  /* padding-top: 44px; */
  position: relative;
}

.home-nav {
  background-color: var(--color-tint);
  color: white;

  /* position: fixed;
  left: 0;
  right: 0;
  top: 0;
  z-index: 9; */
}

.content {
  overflow: hidden;
  position: absolute;
  top: 44px;
  bottom: 49px;
  left: 0;
  right: 0;
}

.tab-control {
  position: relative;
  z-index: 9;
}

/* .content {
  overflow: hidden;
  height: calc(100% - 50px);
} */
</style>